When Does a Cold Sore Stop Being Contagious?

Cold sores are small, fluid-filled blisters that usually appear on or around the lips and mouth. They can appear on their own or in small clusters. In most cases, the blisters will break, creating a scab that eventually falls off. Cold sores are caused by herpes simplex virus type 1 (HSV-1).

HSV-1 is very contagious. You can spread the virus even when you don’t have any symptoms of a cold sore, though you’re usually most contagious when you have them. Cold sores are contagious until they go away completely, which usually takes about two weeks. This means the common belief that cold sores aren’t contagious once they’ve scabbed over isn’t true.

Keep reading to learn more about how cold sores spread and how you can protect those around you when you have one.

HSV-1 is spread by close contact with skin or saliva, such as kissing, oral sex, or even sharing eating utensils or towels. The virus enters the body through a break in the skin, such as a small cut.

Once you’ve contracted HSV-1, you have it for life. However, some people with HSV-1 never have any symptoms. This is because the virus can lie dormant in your nerve cells until something triggers its reactivation. You can still pass the virus to other people while it’s dormant.

HSV-1 is very common. About 50 to 80 percent of people in the United States are living with HSV-1. In addition, most adults are exposed to the virus by the age of 50. However, reactivation of the virus tends to decrease in people over the age of 35

There’s no way to get rid of HSV-1 once you have it. However, there are several things you can do to help manage your symptoms.

Prescription antiviral medication can help speed up the healing process of cold sores. These often come as either pills or creams. For severe infections, you may need an injection of antiviral medication. Common antiviral medications for cold sores include valacyclovir (Valtrex) and acyclovir (Zovirax).

You can also use over-the-counter cold sore treatments, such as docosanol (Abreva), to help heal cold sores.

To reduce redness and swelling, try applying a cold compress or ice cube to the area. You can also take nonsteroidal anti-inflammatory drugs, such as ibuprofen (Advil), to reduce inflammation.

Cold sores are small blisters that occur on and around your lips and mouth. They’re caused by a virus called HSV-1. Once you contract HSV-1, you have the virus for life. While you’ll always be able to spread the virus, you’re most contagious when you have an active cold sore.